Nomad: Non-Destructive Evaluation System for the Inspection of Operation Induced Material Degradation in Nuclear Power Plants

2021 ◽  
Author(s):  
Inge Uytdenhouwen ◽  
Rachid Chaouadi
Keyword(s):  
Evaluation System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Material Degradation ◽  
Non Destructive Evaluation ◽  
Non Destructive

NOMAD: Non-Destructive Evaluation (NDE) System for the Inspection of Operation-Induced Material Degradation in Nuclear Power Plants — Overview of the Neutron Irradiation Campaigns

2020 ◽  
Author(s):  
Inge Uytdenhouwen ◽  
Rachid Chaouadi
Keyword(s):  
Neutron Irradiation ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Pressure Vessels ◽  
Material Heterogeneity ◽  
Non Destructive Evaluation ◽  
Surveillance Programs ◽  
Non Destructive

Abstract Worldwide there are more than 449 nuclear power plants (NPPs) in operation among which 329 reactors are older than 25 years and 94 will be operating for more than 40 years in 2020. Lifetime extensions are requested up to 50–60 years and sometimes even up to 80 years of operation for many existing NPPs. Long-term operation (LTO) of existing NPPs has therefore been accepted in many countries as a strategic objective to ensure supply of electricity for the coming decades. Within this strategy, the European Commission launched the NOMAD project, among others, through the Horizon-2020 programme. The reactor pressure vessels (RPVs) cannot be tested destructively in a direct way, neither can it be replaced. An indirect way is the use of Charpy samples from the so-called surveillance programs. The general strategy on the long term should focus on the ability to perform direct non-destructive evaluation (NDE) of the embrittlement of the vessel. NDE can be used to confirm that the data obtained by surveillance programs are being representative of the real state of the vessel for LTO. Moreover, a generic concern of large nuclear components such as the reactor vessel is the possible material heterogeneity such as macro-segregated regions which could eventually be located in the component but not in the baseline material used as surveillance material. Local non-destructive material inspection and comparison to reference materials in similar irradiation conditions would lead to a better assessment of the properties of the materials at any location of the vessel. The objective of NOMAD is to develop a tool that is capable of non-destructively evaluate the embrittlement of the vessel wall. The final system should be capable of inspecting the microstructure of the materials through the cladding. The tool that will be developed, will use existing and proven nondestructive testing techniques (NDT) with optimized and adjusted sensors. A combination of several techniques based on micro-magnetic, electrical and ultrasonic methods are investigated. Within NOMAD, they are calibrated and validated on a set of existing and newly irradiated samples consisting out of the most common RPV steels from Eastern and Western design, such as 22NiMoCr37, 18MND5, A533-B, A508 Cl.2, A508 Cl.3 and 15kH2NMFA. For the first time, a systematic study on a well-characterized set of samples that correlates the microstructure, mechanical properties, neutron irradiation conditions and non-destructive properties will be carried out. It will not only extend the existing database, but will include issues such as reliability, and uncertainty of the techniques as well as on material heterogeneity. The focus is laid on unbroken Charpy samples and large blocks with and without cladding to “simulate” the actual RPV inspection scenario. This paper gives an overview of the present status of the NOMAD project with focus on the outcome in WP1. The first preliminary NDE results from 6 set-ups and 28 parameters were compared with DBTT results from Charpy impact tests. They are very promising. Final results and detailed analysis will however only be available at the end of the project.

scholarly journals Non-destructive evaluation of containment walls in nuclear power plants

2017 ◽  
Author(s):  
V. Garnier ◽  
C. Payan ◽  
M. Lott ◽  
N. Ranaivomanana ◽  
J. P. Balayssac ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Non Destructive Evaluation ◽  
Non Destructive

Magnetic Barkhausen Noise Method for Characterisation of Low Alloy Steel

2019 ◽  
Author(s):  
Gokulnath Kadavath ◽  
Jino Mathew ◽  
James Griffin ◽  
David Parfitt ◽  
Michael E. Fitzpatrick
Keyword(s):  
Evaluation System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Irradiation Damage ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Material Degradation ◽  
Material Inhomogeneity ◽  
Material State

Abstract Application of NDE techniques to operating reactor materials is useful for the determination of deviations resulting from material inhomogeneity and long-term degradation of properties from irradiation damage. A new programme, Nondestructive Evaluation System for the Inspection of Operation-Induced Material Degradation in Nuclear Power Plants (NOMAD), focuses on the non-destructive investigations of Reactor Pressure Vessel (RPV) steels in ageing reactors to better assess the integrity for lifetime management. In this study, Magnetic Barkhausen Noise (MBN) is used to characterise the effect of inhomogeneties in a Jominy end-quench test specimen subjected to differential cooling rates. The effect of material state encompassing different variables such as surface roughness, microstructure, hardness and residual stress is correlated with the MBN Root Mean Square (RMS) parameter in order to enhance the understanding of the embrittlement phenomena. These studies will contribute to the development of a tool that can monitor and quantify the extent of material degradation in operating nuclear power plants.

A study on accumulator analysis for the valve performance evaluation system of nuclear power plants

Kerntechnik ◽  
2021 ◽  
Vol 86 (1) ◽  
pp. 39-44
Author(s):  
K. Ryu ◽  
T. Lee ◽  
D. Baek ◽  
J. Park ◽  
N. Kim
Keyword(s):  
Latent Heat ◽  
Temperature Difference ◽  
Evaluation System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
High Capacity ◽  
Test System ◽  
Performance Evaluation System ◽  
High Temperature Steam

Abstract To evaluate the valves used in the nuclear power plants are working properly under the required conditions, the performance and capacity test should be performed. In the test system, the accumulator was employed to control the large amount of high pressure and high temperature steam generated in the boiler precisely. In the accumulating process, the steam is often condensed. In order to prevent condensation, it is needed to install heaters and preheat the accumulator. However, if the size of the accumulator becomes large, the installation of the heater may not be easy. Therefore, when the test is conducted, the system was preheated by the latent heat generated from the phase change. Insufficient thermal insulation may cause temperature differences and it can cause mechanical problems in the accumulator structure. If insulation is sufficient, the temperature difference is indicated by the height. As the cooled condensate moves downwards, the condensate is discharged by the drain valve control and the temperature difference of the structure can be disappeared. The results of this paper can be applied to the conceptualization of equipment that uses latent heat and for the design of high-precision steam experimental devices or the design of high-capacity steam utilization systems.

The Geometry of Steam Generator Tube and Its Relevance to the Occurrence of Stress Corrosion Cracking in Operating Nuclear Power Plants

2010 ◽  
Author(s):  
Deok Hyun Lee ◽  
Do Haeng Hur ◽  
Myung Sik Choi ◽  
Kyung Mo Kim ◽  
Jung Ho Han ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Steam Generator ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Corrosion Cracking ◽  
Location Type ◽  
Steam Generator Tubes ◽  
Non Destructive

Occurrences of a stress corrosion cracking in the steam generator tubes of operating nuclear power plants are closely related to the residual stress existing in the local region of a geometric change, that is, expansion transition, u-bend, ding, dent, bulge, etc. Therefore, information on the location, type and quantitative size of a geometric anomaly existing in a tube is a prerequisite to the activity of a non destructive inspection for an alert detection of an earlier crack and the prediction of a further crack evolution [1].

Non-destructive testing of equipment and pipelines in nuclear power plants with RBMK

Atomic Energy ◽  
2012 ◽  
Vol 113 (1) ◽  
pp. 57-63
Author(s):  
Yu. G. Dragunov ◽  
B. P. Strelkov ◽  
A. A. Arefyev ◽  
A. S. Mokrousov ◽  
N. G. Roshchin
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Equipment And Pipelines ◽  
Non Destructive
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